You should always mix it at full strength and dilute to the EC you need for your plants. Then adjust the feeds based on what your plants are showing you.
What I'm saying is don't dilute. I also believe you can probably lower the 3, but the 2 and 1 need to remain at full strength. That why I brought up how using tap water or adding calmag usually gives a reading around 0.2 to 0.4. I think plants need a minimal of that amount of calmag. (Not that it's entirely calmag when dealing with tap, but it gives enough to not cause deficiencies.)
I was diluting down to between 0.8 and 1.2, which was a time amount of magnesium. I think you're better off lowering the 3 than diluting the entire formula down to that low of EC, was my theory. But since I've learned what I've learned in this thread, I'm just going to run at full strength unless I see signs of burns. I was just trying to explain my thought process.